Revision Date: 18/08/03
Technical Advice Sheet
Guide to safe handling of Flexil Hot Melt Compounds
1.
INTRODUCTION
This publication outlines the precautions which should be taken in handling hot melt
compounds made from vinyl chloride polymers (PVC) and copolymers, and has been
prepared in conjunction with the BRITISH PLASTICS FEDERATION.
These plastisols and hot melt compounds are made by blending PVC polymers and/or
copolymers with a variety of additives such as stabilizers, plasticisers, pigments,
fillers etc. Plastisols are liquids or pastes, whilst Hot Melt Compounds are solid,
rubbery doughs in slab or crumb form.
Additional information on individual formulations can be obtained on request.
2.
POTENTIAL HAZARDS
The release of vinyl chloride monomer (VCM) from PVC hot melt compounds into
processing plant atmospheres produces only trace levels well below the limits of the
EEC Directive.
Since there is accepted evidence linking inhalation of high concentrations of VCM
over prolonged periods with carcinogenic effects, precautions are necessary to avoid
inhalation exposure.
An EEC Directive (1) has been issued on the protection of the health of workers
exposed to vinyl chloride monomer. This Directive limits VCM to a technical long
term limit value (TLTLV) of 3 ppm, the reference period being the year, allowing
that where ever practicable, exposures should be brought as near as possible to zero
concentrations. The rigorous monitoring and control measures of the Directive do
not apply to the handling of plastisols or hot melt compounds although it is
recommended that the exposure requirements should be met. Analytical techniques
to measure VCM levels in the atmosphere can be found in a manual published by the
Chemical Industries Association (2).
Compositions based on vinyl chloride/vinyl acetate copolymers also contain trace
residues of vinyl acetate monomer. This is much less volatile than VCM, but will be
slowly released into the surrounding atmosphere. There is no evidence of
carcinogenic effects from vinyl acetate at any concentration. It is recommended
that simple ventilation is employed in areas where plastisols or hot melt compounds
are stored, handled and processed.
INGESTION
Some PVC plastisols or hot melt compounds may contain certain ingredients which
are toxic if ingested. This applies particularly to some of the stabilizer, pigment or
fire retardancy systems used. For this reason, the ingestion of such PVC
compositions may be harmful.
Information contained in this document is the result of careful tests carried out objectively. It has been
produced to aid the Buyer, but without implying any commitment on our part. The Buyer shall remain
responsible for satisfying himself that the products as supplied by us are suitable for his intended purpose.
Since we cannot control the application, process, or use of these products, we cannot accept
responsibility therefore.
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Revision Date: 18/08/03
Technical Advice Sheet
The presence of a toxic ingredient in a PVC plastisol or hot melt compound will be
indicated in the individual technical data sheet for that product, and cautionary
labeling will be found on the containers.
DERMATOLOGY
Whilst PVC polymers and copolymers are not normally considered to be skin irritants
or sensitizing agents in their own right, if sensitizing ingredients are present in the
composition, dermatitic problems could arise. The presence of such an ingredient
will be indicated in the individual technical data sheet and the labeling.
FIRE
PVC plastisols and hot melt compounds under normal conditions of storage and use
are not flammable, but in common with other organic materials they can be
consumed by fire. Some plastisols contain flammable diluents which can constitute
a fire hazard. This information will be given in the individual technical data sheet.
DECOMPOSITION PRODUCTS
The major products of the combustion/thermal decomposition of PVC plastisols and
hot melt compounds are carbon dioxide, carbon monoxide and hydrogen chloride.
Additionally, many minor decomposition products have been identified. Carbon
monoxide and hydrogen chloride are very toxic with threshold limit values of 50ppm
and 5ppm respectively. Inhalation must be avoided. Hydrogen chloride is also very
corrosive. (3) (4)
EXPLOSION
Some PVC plastisols contain diluents which may give rise to a concentration of
vapours which are flammable and potentially explosive.
3.
RECOMMENDED PRECAUTIONS FOR TRANSPORATION HANDLING
AND STORAGE
HEALTH CONSIDERATIONS
PVC plastisols may contain diluents which are flammable and should be stored in
well ventilated conditions as advised by the Local Fire Authority.
Where a person is handling plastisols and hot melt compounds suitable protective
clothing should be worn and the working area should be well ventilated.
FIRE
Most available fire extinguishers are effective in fighting fires involving PVC,
although water based systems should not be used where live electrical equipment is
nearby. Small local fires could be dealt with by personnel in the vincinty, although
care should be taken against inhalation of the decomposition fumes. After
extinguishing the fire, increase ventilation to clear the fumes.
Information contained in this document is the result of careful tests carried out objectively. It has been
produced to aid the Buyer, but without implying any commitment on our part. The Buyer shall remain
responsible for satisfying himself that the products as supplied by us are suitable for his intended purpose.
Since we cannot control the application, process, or use of these products, we cannot accept
responsibility therefore.
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Revision Date: 18/08/03
Technical Advice Sheet
Fire fighting personnel and the Fire Brigade should be informed that PVC is involved
and advised to wear acid resistant protective clothing and full face masks. Suitable
breathing apparatus should be used and qualified medical aid should be sought to
deal with irritation to the skin, eyes, throat etc.
After the fire is extinguished, all affected areas should be washed down to remove
corrosive hydrogen chloride (5)
EXPLOSION
Adequate ventilation should be provided to prevent accumulation of flammable
vapours.
All likely sources of ignitions such as sparks, static discharges and hot surfaces
should be minimized.
4.
RECOMMENDED PRECAUTIONS FOR THE PROCESSING OF PVC
PLASTISOLS AND HOT MELT COMPOUNDS
TEMPERATURE LIMITS
Plastisols and Hot Melt compounds are usually processed at temperatures between
130ºC and 210ºC. Prolonged exposure to these temperatures or a shorter exposure
to higher temperatures will result in decomposition (see section 2.3.2 for
decomposition products). The temperature limits of stability will vary with each
formulation and the processing technique for which it has been designed. Consult
material and equipment suppliers.
VENTILATION AND EXTRACTION
Good ventilation should be provided in all working areas. Adequate extraction
should be provided where hot processing may lead to the formation of fumes.
PROTECTIVE CLOTHING
Good industrial hygiene procedures should be observed when handling PVC plastisols
and hot melt compounds.
Gloves, eye protection and protective clothing should be provided for wear at the
work place, and should be removed before leaving.
FIRE
The recommended fire precautions for processing and fabrication are as in section
3.2.
Information contained in this document is the result of careful tests carried out objectively. It has been
produced to aid the Buyer, but without implying any commitment on our part. The Buyer shall remain
responsible for satisfying himself that the products as supplied by us are suitable for his intended purpose.
Since we cannot control the application, process, or use of these products, we cannot accept
responsibility therefore.
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Revision Date: 18/08/03
Technical Advice Sheet
5.
PERSONAL HYGIENE
Protective clothing should be worn at all times when a risk of exposure to toxic
ingredients has been identified. Washing with soap and water after work and before
eating, drinking and smoking is recommended. Barrier creams may be considered a
sensible precaution.
6.
RECOMMENDED FIRST AID TREATMENT
INHALATION OF NOXIOUS FUMES
The patient should be quickly moved into fresh air. Artificial respiration should be
applied if necessary. Expert medical attention should be obtained immediately.
EYE INJURIES
Plastisols should be flushed from eye by irrigation with water. Expert medical
attention should be sought immediately.
INGESTION
Expert medical attention should be sought immediately.
GENERAL
Where expert medical attention is sought it is important to give details of the
nature of the product being handled.
7.
WASTE DISPOSAL
Disposal of waste is controlled by the “Control of Pollution Act 1974”. Before
disposing of waste plastisols or hot melt compounds , it is recommended that advice
be sought from the Waste Disposal Officer of the Local Authority concerned.
Information contained in this document is the result of careful tests carried out objectively. It has been
produced to aid the Buyer, but without implying any commitment on our part. The Buyer shall remain
responsible for satisfying himself that the products as supplied by us are suitable for his intended purpose.
Since we cannot control the application, process, or use of these products, we cannot accept
responsibility therefore.
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Revision Date: 18/08/03
Technical Advice Sheet
APPENDIX 1. BIBLIOGRAPHY
1.
2.
3.
4.
5.
6.
“EEC COUNCIL DIRECTIVE 78/6/10/EE6 (29 June 1978).” Available from
HMSO.
“The determination of Vinyl Choride: A Plant Manual.” Available from the
Chemical Industries Association.
“Products of combustion of chlorinated plastics.” Coleman and Thomas.
Journal of Applied Chemistry Vol. 4 July 1954.
“The Burning Issue of PVC Disposal.” Clark C.A. SPE Journal Vol. 28 No7, July
1972.
“Threshold Limit Values (Environmental Health Guidance Note EH15).”
Available from Health and Safety Executive.
“Prevention and Control of Fire in the Plastics Processing Industry.” Issued
jointly by the British Plastics Federation and the Fire Protection Association.
APPENDIX 2. ADDRESSES OF SOURCES OF INFORMATION
British Plastics Federation
5 Belgrave Square
London
SW1X 8PH
Chemical Industries Association
Alembic House
93 Albert Embankment
London, SE1 7TU
Fire Protection Association
Fire Prevention Information and Publication Centre
Aldemary House
Queen Street
London EC4N 1TJ
Information contained in this document is the result of careful tests carried out objectively. It has been
produced to aid the Buyer, but without implying any commitment on our part. The Buyer shall remain
responsible for satisfying himself that the products as supplied by us are suitable for his intended purpose.
Since we cannot control the application, process, or use of these products, we cannot accept
responsibility therefore.
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